Cost scaling based successive approximation algorithm for the traffic assignment problem

This paper presents a cost scaling based successive approximation algorithm, called ε-BA (ε-optimal bush algorithm), to solve the user equilibrium traffic assignment problem by successively refining ε-optimal flows. As ε reduces to zero, the user equilibrium solution is reached. The proposed method is a variant of bush-based algorithms, and also a variant of the min-mean cycle algorithm to solve the min-cost flow by successive approximation. In ε-BA, the restricted master problem, implying traffic equilibration restricted on a bush, is solved to ε-optimality by cost scaling before bush reconstruction. We show that ε-BA can reduce the number of flow operations substantially in contrast to Dial’s Algorithm B, as the former operates flows on a set of deliberately selected cycles whose mean values are sufficiently small. Further, the bushes can be constructed effectively even if the restricted master problem is not solved to a high level of convergence, by leveraging the ε-optimality condition. As a result, the algorithm can solve a highly precise solution with faster convergence on large-scale networks compared to our implementation of Dial’s Algorithm B.     

K-Dimension and Holder Exponent for Bush Type Fractal Functions

Bush type fractal functions were defined by means of the expression of Cantor series of real numbers. The upper and lower bound estimates for the K-dimension of such functions were given. In a typical case, the fractal dimensional relations in which the K-dimension equals the box dimension and packing dimension were presented; moreover, the exact Holder exponent were obtained for such Bush type functions.     

Bush型函数图像的K-维数

研究一类基于实数的Cantor级数表示的分形函数———Bush型函数图像的K-维数.得到了这类函数图像的K-维数的上、下界估计式.指出在基于实数的b进制表示的情形下,这类函数图像的K-维数等于其box维数与pack ing维数.     

旋转避障式打草割灌机的研究与应用

介绍了高速公路绿化养护中,如何实现打草割灌机械化作业的方式,及旋转避障式打草割灌机的研究和应用.     

关于客车弹性定位套检验结果异常的分析

对客车弹性定位套外钢套进行常规检验,发现其淬硬层硬度及深度均不符合相应技术要求。采用金相分析、显微硬度测定方法,对该外钢套进行深入分析,认为客车弹性定位套检验结果异常的原因为淬火工艺不当。     

西方人文主义传统、新保守主义与布什原则

“布什原则”的提出，标志着美国抛弃了冷战时期的“遏制与威胁原则”，而代之以更具挑战性、进攻性的所谓先发制人战略。一批主流国际学者对“布什原则”提出的批评虽不无道理，但却忽略了“布什原则”源自西方人文主义传统中的核心战略思想以及与新保守主义的关系。     

公路路基边坡植物防护的探讨

针对新建公路路基边坡不稳定的特性,选择适合于公路路基边坡生态防护的植物品种,分别对草本植物、藤类植物、灌木、小乔木等植物进行了探讨研究,对公路绿化美化具有重要的现实指导意义.